This invention relates to a magnetic actuating mechanism, and, more particularly, to an actuating mechanism including a permanent magnet and an electromagnet.
In many electromagnetic devices, such as relays and circuit breaker trip units, permanent magnets are used to maintain a movable element of the device in a biased position against the actuating force of a spring. The movable element is urged from the biased position when a electromagnetic flux opposing the magnetic flux of the permanent magnet is produced. The electromagnetic flux opposes the magnetic flux of the permanent magnet with sufficient strength to permit the spring to urge the movable element from the biased position. Examples of such devices are described in U.S. Pat. No. 3,783,423 issued Jan. 1, 1974 and U.S. Pat. No. 4,000,481 issued Dec. 28, 1976.
U.S. Pat. No. 4,000,481 describes a magnetic latch which is released by electromagnetic means. The armature and spring of the magnetic latch are held in a retracted position by the force of a magnetic flux field generated by permanent magnets. Energization of an electromagnet coil generates a magnetic flux in opposition to the permanent magnet flux whereby the force of the net flux acting on the armature is insufficient to maintain the armature and spring in the retracted position. Thus, the spring moves the armature to actuate a utilization device.
As with many other electronic components, one of the main goals in developing and improving magnetic actuators is to produce a physically smaller component that will perform as well or better than its larger predecessor. Another goal is to reduce the number of component parts that need to be handled and assembled in producing the component. In the electronic components industry, just a small step toward achieving these goals can mean increased profits and an increased market share. As can be seen in the preferred embodiment of the invention of U.S. Pat. No. 4,000,481, a considerable number of components are needed to construct the magnetic latch.
More specifically, where magnetic actuators are used in circuit breaking device, there is need to decrease the physical size of the magnetic actuators so that the size of circuit breaking devices can also be decreased by reducing the space in the circuit breaking device for the magnetic actuator.
One problem with prior art actuators, such as the latch described in U.S. Pat. No. 4,000,481, is the absence of a simple mechanism to trip the actuator mechanically.